Longitudinal development of hand function in children with unilateral cerebral palsy and its relation to brain lesion and treatment

Abstract

The overall aim of this thesis was to describe the development of hand function in children with unilateral spastic cerebral palsy (CP), and to investigate its relation to brain lesion and treatment. Effective hand use is necessary for task performance and independence in everyday activities. Due to a lesion in the developing brain, children with unilateral CP have difficulties in using the arm and hand on one side of the body, and this motor impairment negatively influences their independence in everyday activities. Therefore, exploration of hand function in children with unilateral CP is essential.

Development of hand function during childhood and adolescence was investigated in studies I and IV, using the Assisting Hand Assessment (AHA) and three other measures of hand function. In study IV, results from 96 children studied at age 18 months to 12 years showed improved use of the affected hand over time, but to a varying extent. The development was rapid at early age, and slowed down and levelled out to a stable performance as the child grew older. Different developmental patterns were found, based on children’s ability. Children with a higher AHA score at 18 months or on a higher MACS level had a faster increase to a higher level. In study I, change in hand function over time in 11 adolescents with unilateral CP 10–21 years of age was investigated. The hand function was found mainly to remain stable during adolescence. Only grip strength increased with age.

Factors assumed to influence development as well as response to training were investigated in studies II and III. In study II, the relation between response to constraint-induced movement therapy (CIMT) and corticomotor organization and brain lesion characteristics was investigated in 16 children aged 10–16 years. The children were evaluated using different measures of hand function, and by transcranial magnetic stimulation to explore the type of corticomotor projections as well as by structural magnetic resonance imaging to describe characteristics of the brain lesion. The results showed that improvement after CIMT was possible irrespective of the type of corticomotor projection and characteristics of the brain lesion. In study III, a possible effect of CIMT in infants below one year of age (baby-CIMT) was explored by using a retrospective design. Use of the affected hand, measured by the AHA at age two, was investigated in a group of 72 children where some had participated in a baby-CIMT programme and others had not. A more favourable use of the affected hand at age two was found in children who had received training before one year of age.

The overall clinical implications of this thesis are that children with unilateral CP increase the use of the affected hand in bimanual activities at an early age and thereafter function at a stable level. The AHA measure at 18 months can be used to predict the future use of the affected hand. CIMT can be offered to children regardless of their underlying pathophysiology, and when adjusted for infants it seems to be an applicable model for improving hand function at young age.